Northstar Engines and System Technical Discussion Discussion, proper torque-to-yield on 99 sts in Cadillac Engine Discussion; I am at the point of tightening my head-bolts, and the FSM says tighten to 30 lbs/ft on first pass, ...

proper torque-to-yield on 99 sts

I am at the point of tightening my head-bolts, and the FSM says tighten to 30 lbs/ft on first pass, second pass -70 degrees, third pass also 70, with final pass at 60 degrees for a total of 200 degrees.
This is not what I have seen listed in several threads? Which method should I use?
I also seem to remember something being mentioned about the timing method listed in the FSM not being correct. I can't for the life of me find that thread back, is
there anything to that? The shop manual seems pretty dang detailed to be incorrect, but, hey, we are all human.
Thanks

Re: proper torque-to-yield on 99 sts

Originally Posted by knon2000

I am at the point of tightening my head-bolts, and the FSM says tighten to 30 lbs/ft on first pass, second pass -70 degrees, third pass also 70, with final pass at 60 degrees for a total of 200 degrees.
This is not what I have seen listed in several threads? Which method should I use?
I also seem to remember something being mentioned about the timing method listed in the FSM not being correct. I can't for the life of me find that thread back, is
there anything to that? The shop manual seems pretty dang detailed to be incorrect, but, hey, we are all human.
Thanks

IIRC, all of the talk about incorrect timing methods in the manual pertain to the 3.6 liter V6....the engine actually has different colored links in the chain instead of timing "marks"......the only strange thing about the N* timing is that if you rotate the crank 720 degrees, the crank mark will NOT line up with the mark on the intermediate sprocket.

Bad call on the Headbolts IMO. If you're sticking with bolts, you should only do so with "Norm's" inserts....and if you use the bolts, you should be using the factory ones......I've heard of problems with aftermarket bolts......

I think there was a TSB that went out about the procedure......and the new procedure puts even more stress on the bolts in an attempt to get a little more clamping force.....but with more failures during installation....

Re: proper torque-to-yield on 99 sts

I made my own inserts. Much better than Norm inserts, at least in my opinion. I don't know that factory bolts would be better than felpro, and considering Jake's well known quality control issues, I really don't feel the least bit worried about using a company with a felpro's quality record.

Re: proper torque-to-yield on 99 sts

Originally Posted by knon2000

I made my own inserts. Much better than Norm inserts, at least in my opinion. I don't know that factory bolts would be better than felpro, and considering Jake's well known quality control issues, I really don't feel the least bit worried about using a company with a felpro's quality record.

Re: proper torque-to-yield on 99 sts

They are longer. I also included the locating dowel on the inserts.
Made it really easy to remove by just drilling them out using the inserted fixture
that I built.
Really helps that I am a machinist with access to the materials that are needed.

Re: proper torque-to-yield on 99 sts

No problem on the torque spec. I was just questioning it since I thought I remember reading a thread where someone was recommending lower starting torque and yeild angles.
I already have the FSM, thanks anyway.
Kevin

Re: proper torque-to-yield on 99 sts

longer is nice but how do you know how much material is at bottom of threaded hole? do you have a block diagram from GM? seen a few comments on cracked blocks due to using oversize thread inserts. sure there is a limit on thread diameter and thread depth. so you might say your inserts are better since they are a "little" longer.

Re: proper torque-to-yield on 99 sts

I used Norm's - before Jake's time - and FelPro bolts - snapped 1 bolt on install. Removed all 10 on that (R) bank, removed the broken remains, Rock Auto sent me a complete new set no charge. All of Norm's inserts were still fine, including the one in the problem hole. No issues the second time around or with the L bank - I think it was a fluke.

I used the 30/70/70/60 procedure.

P.S.: For you guys that know/remember me, Numb Nuts is still driving the car...with no more DUI incidents lately!